Matrix-metalloproteinase-14 deficiency in bone-marrow-derived cells promotes collagen accumulation in mouse atherosclerotic plaques.

Background: Interstitial collagen plays a crucial structural role in arteries. Although in vitro results suggest collagenase activity for membrane-bound matrix metalloproteinase type 1 (MMP-14), in vivo evidence for such a function in atherosclerosis remains scant.

Methods And Results: Because Mmp14-/- mice die by 3 weeks of age, this study used lethally irradiated low-density lipoprotein receptor-deficient mice reconstituted with syngeneic bone marrow cells of Mmp14-/- or Mmp14+/+ mice.

Delta-like 4 induces notch signaling in macrophages: implications for inflammation.

Background: Activated macrophages contribute to the pathogenesis of inflammatory diseases such as atherosclerosis. Although Notch signaling participates in various aspects of immunity, its role in macrophage activation remains undetermined.

Methods And Results: To explore the role of Notch signaling in inflammation, we examined the expression and activity of Notch pathway components in human primary macrophages in vitro and in atherosclerotic plaques.